Induction welding equipment and method for thermoplastic resin matrix composite with internal electromagnetic material

[0029] Embodiment 1: see figure 1 and figure 2 , the thermoplastic resin-based composite material induction welding equipment with built-in electromagnetic material of the present embodiment, comprises induction generator 1, and it is the high-frequency (2-10MHz) power supply that can convert the power supply of 40Hz-70Hz into power generally 1-5KW , the press 3 provides a pre-pressure of 0.45-1.20MPa, which is the pressure head connected to the cylinder or the liquid cylinder; the induction coil 4 and the heat exchanger 2 connected to it, the induction coil 4 can be a single-turn coil, a multi-turn coil, a disk In the form of coil coils, hairpin coils, etc., can be made of copper tube, sheet or machined block, the induction coil is water cooled. Coils can be square, round or rectangular, and the common sizes are 3.2mm, 4.8mm, 6.4mm, 9.5mm. The induction coil 4 is a hollow coil, connected to the heat exchanger 2 for circulating water cooling, the heat insulation plate 9 and the copper shell 10 are fastened to each other, and the external infrared thermometer 8 and its probe 7 are used to detect the temperature of the welding zone of the thermoplastic sheet , to achieve the purpose of precise temperature control, the backing plate 6 is used to place the parts to be welded; the part to be welded 5 is a thermoplastic resin-based composite material with built-in electromagnetic materials, which is made by lamination molding process, and the layer-to-layer During pressing, iron-based ferromagnetic materials are added to form composite weldments. The thickness of the welded composite material is 0.25 mm-5.0 mm, the thickness of each layer of pressed material is 0.05 mm-0.5 mm, and the thickness of the conductive magnetic material is 60-150 μm. The thermoplastic resin-based composite material with built-in electromagnetic material is a composite material in which one or more reinforcing phases are added. For example: fiber reinforced (such as carbon fiber, glass fiber, etc.). The iron-based ferromagnetic material added in the lamination process is powder or granular. Iron-based ferromagnetic materials are added during the lamination process. When any layer is pressed, it is mixed in the thermoplastic resin prepreg in advance, or evenly sprinkled on the surface of any layer.

[0030] Example 2: see figure 1 and 2 , an induction welding method based on the induction welding equipment described in the above-mentioned embodiment 1, specifically placing the composite material welded piece 5 on the backing plate 6, and applying a pre-pressure of 0.45-1.20 MPa to the composite material to be welded by the pressurizing device 3 , and then connect the induction generator 1, the induction generator 1 can convert the 40Hz-70Hz power supply into a high-frequency (2-10MHz) power supply device with a power of 1-5KW, and then give the induction coil a high frequency of 2-10MHz, Generate an electromagnetic field capable of heating the built-in conductive magnetic material 11, and sequentially heat and melt the surrounding thermoplastic resin-based composite material through heat conduction. Since the induction coil 4 is a hollow structure, the heat exchanger 2 can be used to feed into it while the induction coil is working. Circulating water, under the cooling effect of the circulating water, reduces the temperature of the induction coil 4, and when the probe 7 of the infrared thermometer 8 detects that the joint temperature reaches the glass transition temperature of the resin material and is lower than the thermal decomposition temperature, the induction coil 4 stops Working, the joint is allowed to cool to room temperature under constant pressure to form the final joint.

[0031]In the above-mentioned Examples 1 and 2, the production of thermoplastic resin-based composite materials generally adopts a lamination molding process. In the process of pressing between layers, conductive magnetic materials such as iron-based ferromagnetic materials are added to obtain the integration of built-in electromagnetic materials. Thermoplastic resin-based composites. The welding equipment is based on the induction welding equipment of general thermoplastic resin matrix composite materials, and at the same time it is improved to realize axial pressure, and the distance between the joint and the joint can be precisely controlled according to needs, and the efficient welding of induction welding is realized. The welding method is as follows: first, use the pressurization equipment to apply pre-pressure to the composite material to be welded, and then connect the induction coil (working coil) to generate an electromagnetic field to heat the built-in electromagnetic material, and then heat and melt the surface of the thermoplastic resin-based composite material through heat conduction. Under the cooling effect of water, the temperature of the induction coil is reduced. The method has the characteristics of integration of welding materials, reduces the phenomenon of magnetic flux leakage, improves the fatigue strength of joints, and reduces welding stress. In addition, the equipment has the characteristics of integration, and the equipment can be precisely controlled according to needs. There is no need to worry about the melting of the resin material due to the high temperature of the induction coil, which improves work efficiency and reduces energy consumption. At the same time, it realizes axial pressure, which expands the application range of the induction welding method and makes the equipment simpler and lighter. , reduce one-time input and production costs, and have high practicability.